Assumptions can be fairly accurate and good or very inaccurate and very bad. I recently ran across a very bad assumption. A family living in a southern state was found through an obituary in a small town newspaper. That is normally good news but the assumption that was made was that they lived in the town where the newspaper was published. Bad assumption. Why? Because they actually lived in the same county but a few miles away in a different town. The bad assumption came from the wording of the obituary that named the deceased and said that the deceased lived "in this county." But the researchers put the death place as the county seat. Why was this a bad assumption? Because they couldn't find any relatives in the county seat. They all lived way out there in the country.
In this case, the problem was almost fatal and had caused a "brickwall" situation for years in the family's research. After the fact, the solution seems obvious, look further in the county for the family. The place where the family was living actually shows up on U.S. Census and no where else, apparently. It does not even show up as a town listed for that county. Now, why don't I just give you the concrete examples as evidence? First, this isn't my family. My conclusions at this point might be entirely bogus. I don't think so, but if I put out the names and my conclusions and then my conclusions turn out to be wrong, how many people will have already copied my incorrect work into online family trees? I'm not cynical or anything, I speak from personal experience.
So how do we avoid assumptions? Hmm. This sounds like it might get back to the Genealogical Proof Standard. Yep, it does. I think we are making a circle here, I am back to the issue of believing information without proper citations or a reasonably exhaustive search of the records. In the case I cite above, I do not have all of the research the family has done, I just might be re-plowing the field. Why don't I think this is the case? Because with the additional relatives I have found, it is likely that one or more of them can be traced back to the unknown parent. If the family had already checked out all these names, they likely would have already solved their original brickwall question about the identity of the parents of the deceased.
What was the key here? Re-reading the records and asking questions about the information already gathered. No new information was required to crack the code, they already had enough, they just didn't carry it out far enough. Don't get me wrong, I didn't find the parents. Yet. But I am reasonably sure what it will take to find the parents. Will everything I tell the family to do finally answer the question? Possibly yes, possibly no, but they can no longer claim brickwall status for the ancestor because now they have a huge number of records to search. Is this all simple and easy? Not at all. It makes my head hurt.
Especially since just today, one of my genealogy friends told me that whenever I answered a question it made her feel like she didn't know anything because what I said was so complicated she had no idea what I was talking about. Oh well, live and learn. Genealogy is not easy. It is very difficult and like I said, it makes my head hurt sometimes.